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Exosome Complex

  1. Aleksander Chlebowski1,2,
  2. Andrzej Dziembowski1,2

Published Online: 16 JUL 2012

DOI: 10.1002/9780470015902.a0024052

eLS

eLS

How to Cite

Chlebowski, A. and Dziembowski, A. 2012. Exosome Complex. eLS. .

Author Information

  1. 1

    University of Warsaw, Institute of Genetics and Biotechnology, Faculty of Biology, Warsaw, Poland

  2. 2

    Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Warsaw, Poland

Publication History

  1. Published Online: 16 JUL 2012

Abstract

A living cell consists in a dynamic equilibrium of many opposing processes. Steady-state levels of all ribonucleic acid (RNA) and protein molecules result from a specific balance between constant production and ongoing decay. RNA degradation is thus of paramount importance for the cell's wellbeing. A major player in this process is the exosome complex. It is a multisubunit entity endowed with ribonuclease activities. It is highly conserved in evolution, found in all Eukaryota and most Archaea; Eubacteria lack the exosome but they do have a very similar enzyme. The eukaryotic exosome has endo- and exoribonuclease activity and it engages a plethora of substrates in numerous pathways of RNA decay, RNA processing and RNA surveillance. Substrate specificity is conferred by a wide range of cofactors, some of them multisubunit complexes with interaction networks of their own.

Key Concepts:

  • The exosome core is a conserved protein complex.

  • Exosomes of Archaea and Eukaryota have different enzymatic activities.

  • Catalytic activity in eukaryotic exosomes comes from noncore subunits.

  • Catalytic subunits are organised differently in yeast, plants and mammals.

  • The exosome participates in RNA decay, processing and surveillance.

  • Many cofactors are responsible for recruiting substrates to the exosome.

Keywords:

  • exosome;
  • ribonuclease activity;
  • RNA degradation;
  • RNA processing;
  • RNA surveillance;
  • TRAMP complex